Quelle  lru.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0

#include "bcachefs.h"
#include "alloc_background.h"
#include "bkey_buf.h"
#include "btree_iter.h"
#include "btree_update.h"
#include "btree_write_buffer.h"
#include "ec.h"
#include "error.h"
#include "lru.h"
#include "recovery.h"

/* KEY_TYPE_lru is obsolete: */
int bch2_lru_validate(struct bch_fs *c, struct bkey_s_c k,
        struct bkey_validate_context from)
{
 int ret = 0;

 bkey_fsck_err_on(!lru_pos_time(k.k->p),
    c, lru_entry_at_time_0,
    "lru entry at time=0");
fsck_err:
 return ret;
}

void bch2_lru_to_text(struct printbuf *out, struct bch_fs *c,
        struct bkey_s_c k)
{
 const struct bch_lru *lru = bkey_s_c_to_lru(k).v;

 prt_printf(out, "idx %llu", le64_to_cpu(lru->idx));
}

void bch2_lru_pos_to_text(struct printbuf *out, struct bpos lru)
{
 prt_printf(out, "%llu:%llu -> %llu:%llu",
     lru_pos_id(lru),
     lru_pos_time(lru),
     u64_to_bucket(lru.offset).inode,
     u64_to_bucket(lru.offset).offset);
}

static int __bch2_lru_set(struct btree_trans *trans, u16 lru_id,
     u64 dev_bucket, u64 time, bool set)
{
 return time
  ? bch2_btree_bit_mod_buffered(trans, BTREE_ID_lru,
           lru_pos(lru_id, dev_bucket, time), set)
  : 0;
}

int bch2_lru_del(struct btree_trans *trans, u16 lru_id, u64 dev_bucket, u64 time)
{
 return __bch2_lru_set(trans, lru_id, dev_bucket, time, KEY_TYPE_deleted);
}

int bch2_lru_set(struct btree_trans *trans, u16 lru_id, u64 dev_bucket, u64 time)
{
 return __bch2_lru_set(trans, lru_id, dev_bucket, time, KEY_TYPE_set);
}

int __bch2_lru_change(struct btree_trans *trans,
        u16 lru_id, u64 dev_bucket,
        u64 old_time, u64 new_time)
{
 if (old_time == new_time)
  return 0;

 return  bch2_lru_del(trans, lru_id, dev_bucket, old_time) ?:
  bch2_lru_set(trans, lru_id, dev_bucket, new_time);
}

static const char * const bch2_lru_types[] = {
#define x(n) #n,
 BCH_LRU_TYPES()
#undef x
 NULL
};

int bch2_lru_check_set(struct btree_trans *trans,
         u16 lru_id,
         u64 dev_bucket,
         u64 time,
         struct bkey_s_c referring_k,
         struct bkey_buf *last_flushed)
{
 struct bch_fs *c = trans->c;
 struct printbuf buf = PRINTBUF;
 struct btree_iter lru_iter;
 struct bkey_s_c lru_k =
  bch2_bkey_get_iter(trans, &lru_iter, BTREE_ID_lru,
       lru_pos(lru_id, dev_bucket, time), 0);
 int ret = bkey_err(lru_k);
 if (ret)
  return ret;

 if (lru_k.k->type != KEY_TYPE_set) {
  ret = bch2_btree_write_buffer_maybe_flush(trans, referring_k, last_flushed);
  if (ret)
   goto err;

  if (fsck_err(trans, alloc_key_to_missing_lru_entry,
        "missing %s lru entry\n%s",
        bch2_lru_types[lru_type(lru_k)],
        (bch2_bkey_val_to_text(&buf, c, referring_k), buf.buf))) {
   ret = bch2_lru_set(trans, lru_id, dev_bucket, time);
   if (ret)
    goto err;
  }
 }
err:
fsck_err:
 bch2_trans_iter_exit(trans, &lru_iter);
 printbuf_exit(&buf);
 return ret;
}

static struct bbpos lru_pos_to_bp(struct bkey_s_c lru_k)
{
 enum bch_lru_type type = lru_type(lru_k);

 switch (type) {
 case BCH_LRU_read:
 case BCH_LRU_fragmentation:
  return BBPOS(BTREE_ID_alloc, u64_to_bucket(lru_k.k->p.offset));
 case BCH_LRU_stripes:
  return BBPOS(BTREE_ID_stripes, POS(0, lru_k.k->p.offset));
 default:
  BUG();
 }
}

static u64 bkey_lru_type_idx(struct bch_fs *c,
        enum bch_lru_type type,
        struct bkey_s_c k)
{
 struct bch_alloc_v4 a_convert;
 const struct bch_alloc_v4 *a;

 switch (type) {
 case BCH_LRU_read:
  a = bch2_alloc_to_v4(k, &a_convert);
  return alloc_lru_idx_read(*a);
 case BCH_LRU_fragmentation: {
  a = bch2_alloc_to_v4(k, &a_convert);

  guard(rcu)();
  struct bch_dev *ca = bch2_dev_rcu_noerror(c, k.k->p.inode);
  return ca
   ? alloc_lru_idx_fragmentation(*a, ca)
   : 0;
 }
 case BCH_LRU_stripes:
  return k.k->type == KEY_TYPE_stripe
   ? stripe_lru_pos(bkey_s_c_to_stripe(k).v)
   : 0;
 default:
  BUG();
 }
}

static int bch2_check_lru_key(struct btree_trans *trans,
         struct btree_iter *lru_iter,
         struct bkey_s_c lru_k,
         struct bkey_buf *last_flushed)
{
 struct bch_fs *c = trans->c;
 struct printbuf buf1 = PRINTBUF;
 struct printbuf buf2 = PRINTBUF;

 struct bbpos bp = lru_pos_to_bp(lru_k);

 struct btree_iter iter;
 struct bkey_s_c k = bch2_bkey_get_iter(trans, &iter, bp.btree, bp.pos, 0);
 int ret = bkey_err(k);
 if (ret)
  goto err;

 enum bch_lru_type type = lru_type(lru_k);
 u64 idx = bkey_lru_type_idx(c, type, k);

 if (lru_pos_time(lru_k.k->p) != idx) {
  ret = bch2_btree_write_buffer_maybe_flush(trans, lru_k, last_flushed);
  if (ret)
   goto err;

  if (fsck_err(trans, lru_entry_bad,
        "incorrect lru entry: lru %s time %llu\n"
        "%s\n"
        "for %s",
        bch2_lru_types[type],
        lru_pos_time(lru_k.k->p),
        (bch2_bkey_val_to_text(&buf1, c, lru_k), buf1.buf),
        (bch2_bkey_val_to_text(&buf2, c, k), buf2.buf)))
   ret = bch2_btree_bit_mod_buffered(trans, BTREE_ID_lru, lru_iter->pos, false);
 }
err:
fsck_err:
 bch2_trans_iter_exit(trans, &iter);
 printbuf_exit(&buf2);
 printbuf_exit(&buf1);
 return ret;
}

int bch2_check_lrus(struct bch_fs *c)
{
 struct bkey_buf last_flushed;

 bch2_bkey_buf_init(&last_flushed);
 bkey_init(&last_flushed.k->k);

 int ret = bch2_trans_run(c,
  for_each_btree_key_commit(trans, iter,
    BTREE_ID_lru, POS_MIN, BTREE_ITER_prefetch, k,
    NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
   bch2_check_lru_key(trans, &iter, k, &last_flushed)));

 bch2_bkey_buf_exit(&last_flushed, c);
 bch_err_fn(c, ret);
 return ret;

}